BSIAB 2 Not working

Buthut · May 18, 2011, 03:58:36 PM

I bought a GGG BSIAB 2 and got it together only to find out it didn't work. I figured out I accidentally soldered the capacitor on backwards and it blew up while i was taking it off. GGG sent me another one but it was different. Original was 100uF 25v, the one they sent me was 100uF 10v. Not sure if that makes a difference, but it still isn't working.

I tested all of the resistors. All of then tested the right ohms except one. The 1m resistor next to the ground wires makes my meter read 000. I tested my friends BSIAB pedal and his tests correctly. The other 1m resistor on the board tests correctly. I pulled the resistor off cause i thought it was bad and it tests correctly when it is not soldered on the board. Plus the new 1m resistor tests 000 when it was soldered on the board. So something is bad somewhere and i can't trace it down. I can't test capacitors. All the pedal will not do anything on or off. It will not let a signal through to the amp in any state.

Any help would be appreciated.

Thanks,

Govmnt_Lacky · May 18, 2011, 04:18:04 PM

Quote from: Buthut on May 18, 2011, 03:58:36 PM
All the pedal will not do anything on or off. It will not let a signal through to the amp in any state.

If this is the case, and you wired the circuit for True Bypass with a 3PDT switch, then you have either a bad 3PDT switch OR.... your off-board wiring is bad/wrong.

I suspect bad wiring $:-\$

You SHOULD get clean guitar signal if your switch is good AND your off-board wiring is correct. You should start there and get that fixed first. Then try the circuit with the effect on. If it works in bypass but not with the effect on, then you need to go to the next step which would be here:

http://www.diystompboxes.com/smfforum/index.php?topic=29816.0

Good Luck

P.S. Does the LED light up when the effect is engaged?

Buthut · May 18, 2011, 06:54:20 PM

Well I check through the wiring again, and everything is wired the way it should be. There are no wires touching others. And the LED does light up when plugged in to ac power and battery.

Buthut · May 18, 2011, 08:55:45 PM

Also tested every wire to make sure there is no breaks under the shielding. I guess i'm going to pull a switch out of another pedal and try that.

mremic01 · May 18, 2011, 09:22:12 PM

How about the trim pot? I always forget that and start troubleshooting, then I realise I forgot to tweak bias trimpot.

Buthut · May 18, 2011, 09:24:43 PM

Well it was factory at first then today I moved it to the same position as my friends pedal and still nothing.

mremic01 · May 18, 2011, 09:51:34 PM

The trimpot should cut out sound at certain settings. It's for biasing the JFET to 3.4-5.4 volts. GGG Recommends 3.4, but I think 4.5 is what most people bias to. So each time you try messing around with the circuit, I would tweak the pot to see if that gets you some output.

Check your JFETs. If one is soldered in backwards, that would cause problems.

I'm not sure what's up with that resistor, but I wouldn't expect a resistor to measure the correct value once it's soldered to the board. I would just make sure you have a resistor that you know is good in that spot.

If you're not getting output when the pedal is off, you definitely have a wiring issue. That's not going to be something on the board. If you have a DMM, check the lugs on your switch.

Buthut · May 18, 2011, 10:31:14 PM

Ok, i put in a new switch or different one. I got some sound coming out while it is on, but it is real low volume and ALOT of hum. Turning the pedal off results in no sound at all. I adjusted the trim pot but did not get any volume increase. Like I said I check the wiring all around it is as it should be. Would the smaller volt capacitor make any difference?

All other resistors tested within their ohm range with no power to the board but the one 1m resistor, and like I said the one on my friends pedal tested correctly. So I believe something is up with that. It acts like there is no resistance when you touch the leads (like touching the probes of the tester to each other, it zeros out). But when you pull the resistor off the board it tests fine. And my friends tests fine while on the board.
Could there be something wrong with the board?

Buthut · May 18, 2011, 10:32:56 PM

Checked all the pieces on the board several times. The JFets are oriented correctly.

Buthut · May 18, 2011, 11:48:00 PM

Ok, Nevermind, I got it working.

I had replaced the original input jacks with the six prong enclosed ones. Apparently i soldered the output jack wires on the wrong side. Which I don't understand cause they make connection with each other on the inside of the jack.

Please don't think me stupid. I'm really not. LOL!

Govmnt_Lacky · May 19, 2011, 08:53:33 AM

Quote from: Buthut on May 18, 2011, 11:48:00 PM
Ok, Nevermind, I got it working.

I had replaced the original input jacks with the six prong enclosed ones. Apparently i soldered the output jack wires on the wrong side. Which I don't understand cause they make connection with each other on the inside of the jack.

Please don't think me stupid. I'm really not. LOL!

Happens to the best of us.

I just finished a build that I debugged for 4 hours..... before noticing that I missed out on connecting one of the pots to the board

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BSIAB 2 Not working